Systems and methods for alignment of the eye for ocular imaging

ABSTRACT

An ocular alignment system for aligning a subject&#39;s eye with an optical axis of an ocular imaging device comprising one or more guide light and one or more baffle configured to mask the one or more guide light from view of the subject such that the one or more guide light is only visible to the subject when the eye of the subject is aligned with the optical axis of an ocular imaging system.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. patent application Ser. No.14/791,028, filed on Jul. 2, 2015, which claims the benefit of priorityof U.S. Provisional Patent Application Ser. No. 62/020,252 filed on Jul.2, 2014, each of which is incorporated herein by reference for allpurposes.

FIELD OF THE INVENTION

Disclosed herein are systems and methods for alignment of the eye forocular imaging.

BACKGROUND OF THE INVENTION

In ocular imaging, proper alignment of the optical axes of the subject'seye and the imaging optics is a prerequisite to avoid unwantedreflections quality ocular image acquisition. However, there are 12degrees of freedom (6 on the part of the subject's eye, and 6 on thepart of the imaging system, making this a nontrivial task. Traditionalapproaches to achieving alignment rely on an operator manually aligningthe axes of the imaging device to that of the subject's eye, or robotic(automated) alignment of the axes of the imaging system to that of thesubject's eye. Both trained operators and robotic alignment add cost andcomplexity to the imaging workflow. For example, manual handheld funduscameras require the operator to manually position a camera inthree-dimensional space along 6 degrees of freedom, and often require anintegrated screen to view the eye, while the head of the subject ispartially restrained leaving 3 degrees of freedom, for a total of 9degrees of freedom. Traditional manual desk-mounted fundus camerasrequire the operator to manually steer the camera with a joystick, 6degrees of freedom, while the subject's eye is restrained with achinrest and headband as well as fixation, leaving 6 degrees of freedomin total. Automated or semi-automated fundus cameras require complexmotors, additional cameras and sensors, and built-in image processing todrive the automated alignment along 6 degrees of freedom, thereby addingsignificant cost, and also restrain the subject's eye using chinrest,headband and fixation.

The human eye, however, is the endpoint for a highly versatilecybernetic system that can align the optical axis of the eye withrespect to external objects along 6 degrees of freedom. Because there isa need in the art for an alignment system with reduced cost, complexity,and ease of operation, it is attractive to use the natural alignment ofthe human body.

BRIEF SUMMARY OF THE INVENTION

Disclosed herein are various ocular alignment system embodiments foraligning a subject's eye with an optical axes of an ocular imagingdevice. The implementations comprise one or more guide lights and one ormore baffles configured to mask the one or more guide lights from thesubject's eye such that the one or more guide light is only visible tothe subject when the optical axis eye of the subject is aligned with theoptical axis of an ocular imaging system along one or more degrees offreedom.

In certain aspects, disclosed is a device for aligning the optical axisof a subject's eye with the optical axis of an ocular imaging devicecomprising a housing, the housing comprising a first end, a second end,an outer surface, and an inner surface, wherein the inner surfacedefines a luminal space and wherein the luminal space is configured toallow for passage of the optical axis therethrough; a plurality of guidelight assemblies disposed within the housing, each guide light assemblycomprising a body, the body comprising a first side and a second sideopposite the first side, wherein the second side faces the luminal spacea channel defined in the body, wherein the channel extends from the bodyfirst side to the body second side, wherein the channel forms an openingin the body second side; a guide light disposed within the channel,wherein the guide light is configured to emit rays out of the opening;and a baffle disposed transversely in the channel between the guidelight and the opening and configured to mask rays from the guide light,wherein the baffle further comprises a slit configured to allow passageof rays along a path of ocular alignment; and a plurality of secondarybaffle assemblies disposed on the housing second end, wherein each ofthe plurality of second baffle assemblies is configured to mask raysemitted from one of the plurality of guide light assemblies, whereineach of secondary baffle assemblies further comprises a slit configuredto allow passage of rays along a second path of ocular alignment,wherein the rays from each of the plurality of guide light assembliesare visible to the subject when the optical axis of the subject's eye isin alignment with respect to the optical axis of the device and notvisible when the optical axis of the subject's eye is out of alignmentwith respect to the optical axis of the device.

In further aspects, disclosed is a method of aligning the optical axisof a subject's eye with the optical axis of an ocular imaging devicecomprising providing a first set of guide lights along the lineconnecting the optical axes of the subject's eye and of the ocularimaging device; and providing one or more baffles, configured to maskthe rays emitted from first set of guide lights from view of the subjectsuch that first set of guide lights is only visible to the subject whenthe eye of the subject is aligned with the optical axis of an ocularimaging system.

While multiple embodiments are disclosed, still other embodiments of thepresent invention will become apparent to those skilled in the art fromthe following detailed description, which shows and describesillustrative embodiments of the invention. As will be realized, theinvention is capable of modifications in various obvious aspects, allwithout departing from the spirit and scope of the present invention.Accordingly, the drawings and detailed description are to be regarded asillustrative in nature and not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are schematic diagrams of the system, according tocertain embodiments.

FIGS. 2A and 2B are schematic diagrams of the system, according tocertain embodiments.

FIGS. 3A and 3B show schematic diagrams of is a schematic diagram ofguide lights and baffles according to certain embodiments.

FIGS. 4A and 4B are a schematic diagrams of a baffle chambers, accordingto certain embodiments.

FIG. 5 is a schematic diagram of the system according to certainembodiments.

FIG. 6 is a perspective view of the ocular alignment device, accordingto certain embodiments.

FIG. 7 is a side view of the ocular alignment device, according tocertain embodiments.

FIG. 8A is an exploded view of the guide light assembly, according tocertain embodiments.

FIG. 8B is an exploded view of the guide light assembly, according tocertain embodiments.

FIG. 9A shows a view a guide light assembly from the perspective of theluminal space, according to certain embodiments.

FIG. 9B shows a view a guide light assembly and a secondary baffleassembly from the perspective of the luminal space, according to certainembodiments.

FIG. 9C shows a view a guide light assembly and a secondary baffleassembly from the perspective of the luminal space, according to certainembodiments.

FIG. 9D shows a schematic diagram guide light masking by a guide lightbaffle and secondary baffle, according to certain implementations.

FIG. 10 is a perspective view of the ocular alignment device, accordingto certain embodiments.

FIG. 11 is a top view of the ocular alignment device, according tocertain embodiments.

FIG. 12 is a perspective view of the ocular alignment device, accordingto certain embodiments.

FIG. 13 is a bottom view of the ocular alignment device, according tocertain embodiments.

FIGS. 14A and 14B are schematic diagrams of indicator signals accordingto certain embodiments.

DETAILED DESCRIPTION

The instant disclosure relates to optical imaging system embodiments forimaging the eye of a subject which allow a subject to properly positionand align the optical axis of his eye with the optical axis of an ocularimaging system in response to visual cues from the system. This is incontrast to known optical imaging systems where the subject's eyeposition is fixated as much as possible and alignment is achieved byadjusting the position of camera elements with respect to that eye.Thus, the disclosed implementations utilize the precise oculomotoralignment system of the human eye to align to the optical axis of theimaging system, instead of relying on the trained operators or expensiveservo motors to align the optical axis of the imaging system to that ofthe human eye. The disclosed systems are further able to provide forprecise oculomotor alignment without the use of mirrors or lenses todirect light to the desired angle along the optical path.

According to certain embodiments, the system comprises a camera (forexample a fundus camera) having an image sensor and one or more guidelights positioned laterally between the image sensor and the subject'seye. In certain embodiments, the system further comprises one or morebaffles positioned between the one or more guide light and subject'seye. The one or more baffle is configured to occlude the subject's viewof the one or more guide light until the eye of the subject is properlypositioned and aligned translationally (along x, y, z axes). Furtherembodiments have additional lights to provide for alignment rotationally(along θ, η, and ζ axes) with respect to the optical path of the imagingdevice, resulting in optimal image acquisition.

In certain embodiments, as best seen in FIGS. 1 and 2, the guide lightis a ring light 4, which is a light forming a substantially ring-likeshape. As best shown in FIG. 2A, the guide light 4 is masked by a baffle10, which, according to certain embodiments, is of a substantiallycone-like shape with the wide end 12 of the cone-like shaped baffle 10at the ring guide light 4 and the narrow end 14 near the eye of thesubject 2. In certain embodiments, as the subject approaches the device,a coaxial light 8 becomes visible to aid in coarse alignment of thesubject's eye 2 with the system. As the subject directs its gaze intothe device, some section of the guide light ring 4 comes into view. Asthe subject further adjusts its gaze toward alignment, more and more ofthe ring 4 becomes visible until the entire ring 4 is visible indicatingthat the subject's optical axis 11 is in alignment with the to theoptical axis of the imaging system 13 has been achieved. During thisprocess, the aspect of the ring 4 that is not visible will direct thesubject to adjust its eye 2 in the appropriate direction for alignment.For example, if the right side of the ring 4 is fully visible but theleft is not, then the subject adjusts its eye 2 to the right until thelight becomes visible.

According to certain embodiments, best shown in FIG. 1A, the system isexternal to the ocular imaging device 6 (also referred to as a“camera”). For example, in certain embodiments, the guide lights 4 arepositioned on a ring 4 between the objective lens of the camera 6 andthe subject's eye 2. According to certain alternative embodiments, bestshown in FIG. 1B, the system is integrated into the ocular imagingdevice 6. In certain embodiments, the guide lights 4 are positionedaround the objective lens of the camera 6. In further embodiments, theguide lights 4 are positioned within the optics of a fundus camera, orother optical device, in the illumination pathway. In certainembodiments, the guide lights are discretely arranged around the opticalopening of an optical imaging device.

According to certain embodiments, best shown in FIG. 2B, additionaldirection is provided to the subject by providing a sequence of lightsthat serve as sequential focal points. By way of example, a first guidelight or set of guide lights 4 a is activated and the subject aligns itseye 2 with the system such that the guide light 4 or each of the set ofguide lights 4 is visible. Next, a second guide light or set of guidelights 4 b is activated at a point further down the optical path (moredistal from the eye 2 of the subject). The second set of guide lights 4b requires a more precise level of alignment in order to become visibleto the subject, relative to the first guide light or set of guide lights4 a. In certain embodiments, additional subsequent guide lights arepresented to the subject with increasing levels of precision required ofthe alignment in order for the lights to become visible. As the subjectaligns its eye 2 with each of the sequential focal points, the subject'seye 2 is guided along the z-axis until they are looking at the targetring of light.

In certain embodiments, one or more of the guide lights 4 areimplemented as collimated light sources such as laser light. In theseembodiments, the one or more guide lights 4 can be direct along aspecific path configured to be visible only when the eye 2 is properlypositioned. Accordingly, in these implementations, baffles are no longernecessarily needed.

FIGS. 3A and B show exemplary baffles 16, 18 according to certainembodiments. In these embodiments, light emitted from the guide light 4is constrained by a first baffle 16 and a second baffle 18. The firstbaffle 16 and second baffle 18 define a gap 20 through which a guidelight beam 22 along the alignment path is emitted. As will beappreciated by one skilled in the art, the angle of the baffle(s) 16, 18constrains the light emission such that only a beam 22 at the desiredbeam path angle is emitted, allowing for precise control of the positionof the eye required for viewing the masked light. As best shown in FIG.3B, baffle angle can be adjusted to produce emission of the alignmentbeam 22 at the desired angle.

In certain alternative embodiments, the one or more guide lights arefurther comprised of sets of guide lights, wherein each set isconfigured to achieve alignment with respect to a specific axis (notshown). For example, according to certain embodiments, the plurality ofguide lights are further comprised of one or more of z-axis guidelights, configured to be visible when the subject's eye is optimallypositioned along the z-axis with respect to the image sensor. Theplurality of guide lights are further comprised of one or more x-axisguide lights and one or more y-axis guide lights, configured to bevisible to the subject when the subject is optimally positioned andaligned along the x-axis and y-axis, respectively.

According to certain implementations, best shown in FIG. 4A, each of theone or more guide lights 4 is enclosed within a baffle chamber 52. Thebaffle chamber 52 is defined by baffle walls 54 and has a first end 56,at which the guide light is positioned, and a second end 58, from whichthe light is emitted. In certain embodiments, the baffle chamber 52narrows from the first end 56 to the second end 58, and in certainembodiments, forms a substantially cone-like shape. In certainimplementations, light is emitted from the second end 58 through abaffle chamber slit 60. The baffle chamber slit 60 ensures that onlylight that leaves the baffle chamber 52 is traveling at the proper angleto achieve alignment with the subjects eye (not shown). According tocertain embodiments, the baffle chamber walls 54 are comprised of ananti-reflective material, thus further ensuring that only light at theproper angle leaves the baffle chamber 52. In further embodiments, airpockets or voids within the baffle chamber 52 are employed to furtherminimize reflection. According to certain embodiments, best shown inFIG. 4B, the According to certain embodiments, best shown in FIG. 13,the baffle slits 60 are angled toward the center of the optical path 57.In certain implementations, the baffle chamber is a guide lightassembly, a described elsewhere herein.

In certain implementations, best shown in FIG. 5, there are multiplebaffle chambers 52. In this specific example, there are three bafflechambers 52. The guide lights 4 are disposed within the baffle chambers52 and the baffle chambers 52 are mounted on a housing 64 configured tointerface with an optical imaging device 6. According to certainembodiments, the baffle chambers 52 are pivotally mounted on the housing64, such as by way of a hinge 62. In these embodiments, the angle of thebaffle chamber 52, and thus the angle of the emitted guide light beam51, is adjusted according to the desired ocular alignment point 53.According to certain implementations, the pivotal movement of the bafflechambers 52 around their hinges 62 is driven by an electric motor or thelike so that the baffle chambers 52 can be pivoted according topredetermined angles corresponding with various desired points ofalignment.

According to further embodiments, best shown in FIGS. 6-10, disclosed isan alignment device 63 for aligning the eye 2 of a subject with anocular imaging device (not shown). In these implementations thealignment device 63 comprises a housing 64 with a first end 66, a secondend 68, an outer surface 70, and an inner surface 72 (as best shown inFIG. 7). The housing 64 first end 66 is configured to interface with anocular imaging device (such as, for example, a device similar to thedevice 6 embodiments shown in FIGS. 1A-2B and 5) while the second end 68is proximal to the eye 2 of the subject. According to certainimplementations as best shown in FIGS. 7 and 11, the housing 64 is asubstantially tubular shape defining a luminal space 82 defined by itsinner surface 72 through which the optical path 80 (as shown in FIG. 6)between the optical imaging device and the eye 2 of the subject canpass. As best shown in FIGS. 7 and 12, a plurality of guide lightassemblies 74 is arranged on the housing 64.

As best shown in FIGS. 7-8B, the guide light assemblies 74 comprise abody 76 having a first side 84 extending from the housing outer surface70 and a second side 86 facing the luminal space 82. In certainimplementations, also best shown in FIGS. 7-8B, the guide lightassemblies 74 are slidably mounted into the housing 64 such that theuser can adjust the position of the guide light assembly 74 along alongitudinal axis 71.

As best shown in FIGS. 8A and 8B, the guide light assembly body 76defines a channel 88 extending from the guide light assembly body firstside 84 to the second side 86 as best shown via the longitudinal axisdepicted schematically via line A in FIG. 8A. The channel forms a firstopening 88 a on guide light assembly body first side 84 and a secondopening 88 b guide light assembly body second side 86. Disposed withinthe channel 88 is a guide light bezel 73 and a guide light 77 disposedwithin the guide light bezel 73 (best shown in FIG. 8A). As best shownin FIGS. 7 and 10-13, the guide light bezel 73 is disposed partiallywithin the channel 88 such that a portion of the bezel 73 extends out ofthe channel 88 on the first side 84. In certain implementations, theguide light assembly may further comprise a power supply, housed withinthe body (not shown).

Continuing with FIGS. 8A and 8B, the guide light assembly 74 furthercomprises a baffle 90 positioned in the channel 88 at or near the secondchannel opening 88 b on the second side 86 (disposed between the guidelight 77 and the second channel opening 88 b). As shown, the baffle 90is positioned such that it is transverse to the longitudinal axis of thechannel 88. The baffle 90 has a slit 92 defined in the baffle 90 that ispositioned longitudinally along the length of the baffle 90. In use, thebaffle 90 occludes rays emitted by the guide light 77, while the slit 92permits passage of rays traveling along the alignment path 99 (bestshown in FIG. 9A).

According to certain embodiments, the device further comprises aplurality of secondary baffle assemblies 96 (best shown in FIGS. 7 and10-13). According to certain embodiments, the plurality of secondarybaffle assemblies 96 is arranged on the second end 68 of the housing 64such that the baffle assemblies 96 extend inward toward the center ofthe luminal space 82, as best shown in FIG. 12. In certainimplementations, as best shown in FIG. 7, the secondary baffleassemblies 96 are slidably mounted into the housing 64 such that theuser can adjust the position of the secondary baffle assembly 96 along alongitudinal axis 71. As best shown in FIGS. 9 and 12, each of thesecondary baffle assemblies 96 further comprise a baffle plate 101 and abaffle wall 108 extending into the luminal space 82, as mentioned above.The baffle plate 101 further comprises a slit 98.

As best shown in FIG. 9C, light 97 emitted from the slit (not shown) inthe baffle 90 is further masked by the secondary baffle assembly 96,with the baffle plate 101 and the baffle wall 108 blocking light 97 notalong the alignment path. The slit 98 mentioned above is configured toallow passage of guide light rays 99 along the path of alignment. Aswill be appreciated by a person having skill in the art, adjustment ofthe guide light assembly or the secondary baffle assembly 96 along thelongitudinal axis 71 permits the adjustment of the angle at which theguide light rays 99 are emitted and masked. Such adjustment makes itpossible to modify the alignment points with respect to the eye of thesubject 2.

According to certain embodiments, the baffle slit 92 and the secondarybaffle assembly 96 slit 98 have a generally perpendicular orientationwith respect to one another. FIG. 9D shows a schematic representation ofthe effect of slit orientation on light masking. As shown in thatfigure, rays 97 are emitted along the length of the baffle slit 92. Thesecondary baffle assembly 96 masks all rays 97 except for ray at theproper alignment path 99 which passes through the secondary baffleassembly slit 98 and is perceptible to the subject's eye 2, indicatingproper alignment.

The disclosed devices and systems are capable of imaging multiple ocularregions. In certain embodiments, proper alignment is achieved when thesubject's eye is aligned for imaging of the retina. In furtherembodiments, proper alignment is achieved when the subject's eye isaligned for imaging the cornea. In still further embodiment, properalignment is achieved when the subject's eye is aligned for imaging theiris. In yet further embodiments, proper alignment is achieved when thesubject's eye is aligned for imaging the lens. In further embodiments,proper alignment is achieved when the subject's eye is aligned forimaging the optic nerve head.

As will be appreciated by a person having skill in the art, thedisclosed systems and devices can be used with numerous optical imagingsystems. In certain embodiments, the optical imaging device is a funduscamera. In further embodiments, the camera is an optical coherencetomography (OCT) retinal camera. In still further embodiments, theoptical imaging device is an autorefractor. In yet further embodiments,the optical imaging device is a corneal camera. As will be appreciatedby one skilled in the art, other camera types are possible.

According to certain embodiments, the system further comprises one ormore indicator signals. In these embodiments, each indicator signalserves to provide additional guidance to the subject regarding therequired direction of eye movement to achieve alignment. Exampleindicator signals include, but are not limited to, arrows, colors, orflashing lights. In certain implementations, sounds and/or othernon-visual feedback cues are also possible. According to certainembodiments, the indicator signals are masked by one or more bafflessuch that they are only visible when the eye is out of alignment. Forexample, a rightward pointing arrow indicator signal is baffled suchthat it is only visible to the subject when the subject eye is directedto the left of proper alignment.

According to certain embodiments, indicator signals are comprised ofcolored ring lights of differing colors (not shown). The one or moreguide lights is a color different from the colors of the one or moreindicator signal. FIG. 14A shows an eye of a subject 2 out of alignmentwhere the subject is able to view a red indicator signal light 102 butunable to see the green guide light 106. Similarly, if the subject isable to view the yellow indicator signal 104, its eye 2 is not in properalignment. FIG. 14B shows an eye of a subject in proper alignment wherethe subject is able to see the green guide light 106 but unable to seethe yellow 104 or red indicator signals 106. According to certainembodiments, (not shown) the indicator signal the subject is able toview conveys information to the subject about the direction the eyeneeds to adjust in order to achieve proper alignment.

In certain aspects, disclosed is a device for aligning a subject's eyewith an optical axis of an ocular imaging device comprising a housing,the housing comprising a first end, a second end, an outer surface, andan inner surface, wherein the inner surface defines a luminal space andwherein the luminal space is configured to allow for passage of theoptical axis therethrough; a plurality of guide light assembliesdisposed within the housing, each guide light assembly comprising abody, the body comprising a first side and a second side opposite thefirst side, wherein the second side faces the luminal space a channeldefined in the body, wherein the channel extends from the body firstside to the body second side, wherein the channel forms an opening inthe body second side; a guide light disposed within the channel, whereinthe guide light is configured to emit rays out of the opening; and abaffle disposed transversely in the channel between the guide light andthe opening and configured to mask rays from the guide light, whereinthe baffle further comprises a slit configured to allow passage of raysalong a path of ocular alignment; and a plurality of secondary baffleassemblies disposed on the housing second end, wherein each of theplurality of second baffle assemblies is configured to mask rays emittedfrom one of the plurality of guide light assemblies, wherein each ofsecondary baffle assemblies further comprises a slit configured to allowpassage of rays along a second path of ocular alignment, wherein thelight from each of the plurality of guide light assemblies is visible tothe subject when the subject's eye is in alignment with respect to theoptical axis and not visible when the optical axis of the subject's eyeis out of alignment with respect to the optical axis.

According to further aspects the plurality of guide light assemblies areslideably mounted to the housing. In yet further aspects, the pluralityof secondary baffle assemblies are slidably mounted to the housing. Inyet further aspects, the secondary baffle assemblies each furthercomprise a baffle plate, wherein the slit is positioned on the baffleplate, and a baffle wall. the baffle wall extends into the luminal spaceof the housing toward the housing first end. In even further aspects, atleast one of the plurality of secondary baffle assemblies is comprisedof anti-reflective material.

In certain implementations, the disclosed device further comprises aco-axial light, visible to the subject when the subject's is in coarsealignment. In certain aspects, the disclosed device further comprises afirst set of the plurality of guide lights wherein the first set ofguide lights is visible to the subject when the optical axis of thesubject's eye is in alignment along a x-axis with respect to the opticalaxis of the ocular device; and a second set of guide lights, visible tothe subject when the optical axis of the subject's eye is in alignmentalong a y-axis with respect to the optical axis of the ocular device,wherein when the first set of guide lights and second set of guidelights are simultaneously visible to the subject, the subject's eye isin alignment with the z-axis.

In certain aspects, disclosed is an ocular alignment system for aligningthe optical axis of a subject's eye with an optical axis of an ocularimaging device comprising a plurality of guide lights; and one or morebaffle configured to mask the one or more guide light from view of thesubject such that the one or more guide light is only visible to thesubject when the optical axis of the subject's eye is aligned with theoptical axis of an ocular imaging system.

In further aspects, at least one of the plurality of guide light is aring light. In still further aspects, a set of the plurality of theplurality of guide lights is perceptible to the subject as varyingspatial patterns indicating the direction of eye movement required foralignment. In yet further aspects, each of the plurality of guide lightsis comprised of a distinct light source. In even further aspects, thedisclosed system further comprises one or more sets of guide lightswherein one or more guide lights or regions of guide lights are turnedon or off in different patterns for different optical fixation points.

In further aspects one or more baffle is a cone. In still furtheraspects, the one or more baffle further comprises one or more slits,configured to allow passage of rays along the alignment path. In evenfurther aspects, the one or more baffles further comprises an air cavityor light absorption materials in combination or separately to minimizeguide light reflection. In further aspects, the plurality of baffles orguide lights are adjustable to control a z-axes focal point to thesubject's eye.

According to certain aspects, the disclosed system further comprising afirst set of the plurality of guide lights wherein the first set ofguide lights is visible to the subject when the subject's eye is inalignment along a x-axis with respect to the optical axis; and a secondset of guide lights, visible to the subject when the subject's eye is inalignment along a y-axis with respect to the optical axis, wherein whenthe first set of guide lights and second set of guide lights aresimultaneously visible to the subject, the subject's eye is in alignmentwith the z-axis. In still further aspects, a set of the plurality ofguide light is only visible when the eye is aligned along the x, y and zaxes with respect to the optical path of the ocular imaging device. Inyet further aspects, the one or more guide light sources is positionedin the x-y plane at varying z-distance to optimize guide light path(s)to the subject. According to certain aspects, the one or more guidelight is only visible when the eye is aligned along the θ, η, and ζ axeswith respect to the optical path of the ocular imaging device.

According to certain implementations, the disclosed system furthercomprises one or more indicator signals, wherein the one or moreindicator signals indicates to the subject a direction of eye movementto achieve alignment. In certain aspects, the disclosed system furthercomprises one or more baffles to mask the one or more indicator signalsfrom view of the subject such that the one or more indicator signal isonly visible to the subject when the optical axis of the eye of thesubject is out of alignment with the optical axis or a targetoperational distance of the ocular imaging system. In certain aspects,one or more indicator signals are arrows. In further aspects, the one ormore indicator signals are colored lights.

According to certain aspects, the disclosed ocular alignment system isintegrated within optical imaging device. In further aspects, the ocularalignment system is external to the optical imaging device.

According to certain implementations, the disclosed system furthercomprises a coaxial light, visible to the subject when coarse alignmentis achieved.

In certain aspects, disclosed is a method of aligning a subject's eyewith an optical axis of an ocular imaging device comprising providing afirst set of guide lights along the optical path between the subject'seye and the ocular imaging device and providing one or more baffle,configured to mask the first set of guide lights from view of thesubject such that first set of guide lights is only visible to thesubject when the optical axis of the subject's eye is aligned with theoptical axis of an ocular imaging system.

In certain aspects, the first set of guide lights is visible to thesubject when the optical axis of the subject's eye is in alignment alonga x-axis with respect to the optical axis of the ocular imaging device,and the method further comprises providing a second set of guide lights,visible to the subject when optical axis of the subject's eye is inalignment along a y-axis with respect to the optical axis of the ocularimaging device; and wherein when the first set of guide lights andsecond set of guide lights are simultaneously visible to the subject,the subject's eye is in alignment with the z-axis.

In certain aspects, the disclosed method further comprises providing aset of indicator lights visible to the subject when the subject's eye isout of alignment. In yet further aspects the indicator signals arecomprised of no-visual signals, including but not limited to auditoryand tactile indicator signals. In further aspects, the disclosed methodfurther comprises providing a sequence of guide lights, wherein eachguide light in the sequence brings the subject's eye closer to alignmentalong the z-axis with respect to the optical axis of the ocular imagingsystem.

Although the present invention has been described with reference topreferred embodiments, persons skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

What is claimed is:
 1. A device for aligning a subject's eye with anoptical axis of an ocular imaging device comprising: a. a housingcomprising a first end, a second end, an outer surface, and an innersurface, wherein the inner surface defines a luminal space and whereinthe luminal space is configured to allow for passage of the optical axistherethrough; and b. a plurality of guide light assemblies, each guidelight assembly comprising: i. a body comprising a first side and asecond side opposite the first side, wherein the second side faces theluminal space; ii. a channel defined in the body, wherein the channelextends from the body first side to the body second side, wherein thechannel forms an opening in the body second side; iii. a guide lightdisposed within the channel, wherein the guide light is configured toemit light out of the opening; and iv. a baffle disposed transversely inthe channel between the guide light and the opening and configured tomask light from the guide light, wherein the baffle further comprises aslit configured to allow passage of light along a path of ocularalignment; and wherein the light from each of the plurality of guidelight assemblies is visible to the subject when the subject's eye is inalignment with respect to the optical axis of the ocular imaging deviceand not visible when the subject's eye is out of alignment with respectto the optical axis of the ocular imaging device.
 2. The device of claim1, wherein the plurality of guide light assemblies are slideably mountedto the housing.
 3. The device of claim 1, further comprising a pluralityof secondary baffle assemblies disposed on the housing second end,wherein each of the plurality of second baffle assemblies is configuredto mask light emitted from one of the plurality of guide lightassemblies, wherein each of secondary baffle assemblies furthercomprises a slit configured to allow passage of light along a secondpath of ocular alignment and wherein the plurality of secondary baffleassemblies are slidably mounted to the housing.
 4. The device of claim3, wherein the secondary baffle assemblies each further comprise abaffle plate, wherein the slit is positioned on the baffle plate, and abaffle wall.
 5. The device of claim 4, wherein the baffle wall extendsinto the luminal space of the housing toward the housing first end. 6.The device of claim 1, wherein the secondary baffle assembly arecomprised of anti-reflective material.
 7. The device of claim 1, furthercomprising a co-axial light, visible to the subject when the subject'sis in course alignment.
 8. The device of claim 1, further comprising afirst set of the plurality of guide lights wherein the first set ofguide lights is visible to the subject when the subject's eye opticalaxis is in alignment along the x-axis with respect to the optical axisof the imaging system; and a second set of guide lights, visible to thesubject when the subject's eye optical axis is in alignment along ay-axis with respect to the optical axis of the imaging system, whereinwhen the first set of guide lights and second set of guide lights aresimultaneously visible to the subject, the subject's eye is in alignmentwith the z-axis of the imaging system.
 9. An ocular alignment system foraligning the optical axis of a subject's eye with an optical axis of anocular imaging device comprising: a. a first set of a plurality of guidelights visible to the subject when the optical axis of the subject's eyeis in alignment along the x-axis with respect to the optical axis of theocular imaging system; and a second set of guide lights, visible to thesubject when the subject's eye is in alignment along a y-axis withrespect to the optical axis of an ocular imaging system, wherein whenthe first set of guide lights and second set of guide lights are visibleto the subject, the subject's eye is in alignment with the z-axis; andb. one or more baffle configured to mask the one or more guide lightfrom view of the subject such that the one or more guide light is onlyvisible to the subject when the optical axis of the subject's eye isaligned with the optical axis of an ocular imaging system.
 10. Thesystem of claim 9 wherein the one or more baffle further comprises oneor more slits, configured to allow passage of light along the alignmentpath.
 11. The system of claim 9 wherein the plurality of baffles orguide lights are adjustable to control a z-axes focal point to thesubject's eye.
 12. The system of claim 9 wherein a set of the pluralityof guide light is only visible when the eye is aligned along the x, yand z axes with respect to the optical path of the ocular imagingdevice.
 13. The system of claim 9, where the one or more guide lightsources is positioned in the x-y plane at varying z-distance to optimizeguide light path(s) to the subject.
 14. The system of claim 13 whereinthe one or more guide light is only visible when the eye is alignedalong the θ, η, and ζ axes with respect to the optical path of theocular imaging device.
 15. The system of claim 9, further comprising oneor more indicator signals, wherein the one or more indicator signalsindicates to the subject a direction of eye movement to achievealignment.
 16. The system of claim 15, further comprising one or morebaffle to mask the one or more indicator signal from view of the subjectsuch that the one or more indicator signal is only visible to thesubject when the eye of the subject is out of alignment with the opticalaxis or a target operational distance of the ocular imaging system. 17.The system of claim 9 further comprising a coaxial light, visible to thesubject when coarse alignment is achieved.
 18. A method of aligning asubject's eye with an optical axis of an ocular imaging devicecomprising: a. providing a first set of a plurality of guide lightsvisible to the subject when the optical axis of the subject's eye is inalignment along the x-axis with respect to the optical axis of theocular imaging system; and a second set of guide lights, visible to thesubject when the subject's eye is in alignment along a y-axis withrespect to the optical axis of an ocular imaging system, wherein whenthe first set of guide lights and second set of guide lights are visibleto the subject, the subject's eye is in alignment with the z-axis. 19.The method of claim 18, further comprising providing one or moreindicator signals, wherein the one or more indicator signals indicatesto the subject a direction of eye movement to achieve alignment.
 20. Themethod of claim 18, further comprising the step of providing one or morebaffle, configured to mask the first set of guide lights from view ofthe subject such that first set of guide lights is only visible to thesubject when the eye of the subject is aligned with the optical axis ofan ocular imaging system.